Asthma: acute exacerbation: continuous albuterol nebulisers were better than intermittent ones.

Clinical bottom line (level 1b)

  1. Patients with acute asthma who received continuous albuterol nebulisers had a greater improvement in FEV1 at 2 hours compared with patients who received intermittent nebulisers.
  2. Patients on low dose continuous nebulisers received the same benefit as patients on high dose intermittent nebulisers.
  3. The frequency of side-effects were not clearly different.
Shrtestha et al: Chest 1996; 110 (1): 42-47
Expires November 2002

The study

Unblinded concealed randomised trial without intention-to-treat
Setting: university hospital, USA

159 patients (aged mean 34 years, 51% female) with acute asthma, and FEV1 < 40% predicted

Excluded if
  • <18
  • pregnant or breast-feeding
  • incarcerated
  • history of allergy to albuterol
  • unable to speak or understand English


    • Control Group: (n = 42, 42 analysed): 2.5 mg albuterol nebulised every hour
    Experimental Group: (n = 40, 40 analysed): 7.5 mg albuterol nebulised every hour
    Experimental Group: (n = 38, 38 analysed): 2.5 mg/hour continuous albuterol nebulised
    Experimental Group: (n = 37, 37 analysed): 7.5 mg/hour continuous albuterol nebulised

    100% followed for 2 hours

    The evidence

    low dose albuterol vs high dose albuterol
    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    tremor 2 hours 9
    (11.3%)    		 17
    (22.1%)    		 -96%
    (-313% to 7%)    		 -10.8%
    (-22.4% to 0.74%)    		 -9
    (NNT = 140 to infinity;
    NNH = 4 to infinity)

    Outcome Control Group
    (SD)    		 Experimental Group
    (SD)    		 Mean Difference
    (95% CI)
    increase in FEV1 (l) with intermittent 2.5 mg
    ()     		0.72
    (0.50)
    ( to )
    increase in FEV1 with intermittent 7.5 mg
    ()     		0.90
    (0.57)     		0.18
    (0.06 to 0.42)
    increase in FEV1 with continuous 2.5 mg
    ()     		1.02
    (0.58)     		0.30
    (0.06 to 0.54)
    increase in FEV1 with continuous 7.5 mg
    ()     		1.07
    (0.69)     		0.35
    (0.06 to 0.64)

  • One patient (in the high dose continuous group) developed hypokalaemia < 3.0 mmol/l.

    • Comments

    1. Short follow-up and lack of clinically important outcomes makes the results less clinically relevant.
    2. How do continuous nebulisers compare to MDI/spacer beta-agonists?

    Citation

    1. Shrtestha M, Bidadi K, Gourlay S, et al: continuous vs intermittent albuterol at high and low doses, in the treatment of severe acute asthma in adults. Chest 1996; 110 (1): 42-47
    Contributor: Chris Ball and Clare Wotton, November 2000
    Reviewer: Mitsuhiro Kamei

    Clinical Question.
    Patient asthma
    Intervention or Exposure continuous albuterol nebulisers
    Comparison intermittent nebulisers
    Outcome FEV1